Truck for underhung type overhead crane



April 1961 w. E. WASON 2,978,992

TRUCK FOR UNDERHUNG TYPE OVERHEAD CRANE 5 Sheets-Sheet 1 Filed July 16, 1959 JNVENTOR. WALLACE E. WASON ATTOR N EYS April 11, 1961 w. E. WASON 2,978,992

TRUCK FDR UNDERHUNG TYPE OVERHEAD CRANE Filed July 16, 1959 3 Sheets-Sheet a FIG. 4

IN V EN TOR. WALLACE E. WASON Jay 6 Fag ATTORNEYS States Wallace E. Wason, Cleveland, Ohio, assignor to Mechanical Equipment Co., Inc., Cleveland, Ghio, a corporation of Ohio Filed July 16, 1959, Ser. No. 827,566

1 Claim. (Cl. 105-154) This invention is particularly directed to a novel type truck and drive means therefor for an underhung type overhead crane. By way of general introduction, underhung type overhead cranes may consist of three types: (1) the Monorail cranes which operate on hardened special dimension tracks with a specific crane operated on a specifically sized runway rail; (2) the hand-operated underhung cranes which operate on structural I-beams and are for limited use, being constructed with plain bearings and built to sell at low price and for a specifically sized beam; and (3) the motor driven underhung cranes which operate on structural I-beams and are quality built, providing good bearing design, better material in the wheels and heavier construction throughout. This latter type crane is again constructed for a specifically sized runway beam, although there are a few exceptions.

As to the first of the three types of underhung type overhead cranes, it may be said in general that the Monorail type cranes are of rather limited capacity, using many small wheels to spread the load along lightweight track and guiding the cranes by flanged wheels or by side guide rollers bearing against the edge of the beam flange, and are made up of many small high-speed parts.

With respect to the hand-operated underhung cranes, it may be said in passing that this second type of crane uses soft cast-iron wheels, cast-iron cross shaft bearings, a gear and pinion drive at the end truck and guides the crane by the use of wheel flanges. These tend to bind and cause peening of the runway rails.

The third type of crane or the motor driven I-beam creme uses hardened cast-iron or steel wheels, anti-friction cross shaft bearings but still depends on wheel flanges to guide it. Using wheel flanges causes the load to be at the extreme edge of the I-beam flange and peening of the rail results. This type unit uses a pinion and gear reduction t the end trucks to propel the crane and is restricted to this type drive because of the binding action of the wheel flanges or sliding action of wheels tapered to mate with the lbeam tapers.

This invention is directed to a truck that may be used in a wide range of I-beam sizes and that is unlimited over a wide range of standard I-beams. This truck is constructed out of standard components and used with a crane bridge of varying lengths. It is characterized by having crowned wheels on the underhung type overhead crane which ride on the flanges of structural I-beams. It is driven by a rubber or resilient mounted tire shimmed to the underside of the crane bridge truck, and there are standard electric motors, reduction gears and shaftingused which extend to The drive means may vary making the-unit useful for push type cranes, hand-geared cranes or motor driven cranes. In this connection, it is to be understood thatin certain shops it is not necessary to have them all motor driven with the associated controls which results in a great increase in cost. In fact, they need not be handgeared in certain instances since a push type crane may be used. This type of truck will operate with all of the varying drive means.

Each truck is characterized by having a rubber tire friction drive on the underside and an underhung drive and crowned wheel structure which rides on the tapered flanges of the beam, together with a, plurality of side guide rollers to contact the web of the structural Ibeam in the event of distortion or slippage.

The crowned wheels are made of steel with induction hardened treads developing a Brinell hardness in the range 450-500. The contour of the wheel tread is a @ecial double radius that provides a crowned wheel. There are absolutely no flanges on the wheels so that the specific dimensions'of the structural I-bearn, outwardly from the point of contact'with the crowned wheels, are of no import provided the end truck is built sufliciently big to fit outside an I-beam of varying dimension. It further can be seen, because of the fact that these crowned wheels are operated substantially parallel to the web of the flange and perpendicular to the lower flat face of the I-beam, that they will operate only on one-half of the crowned wheel against the outwardly tapered flange and may be reversed to the opposite wheel mounting so that the opposite face of the crowned wheel may be worn to provide additional usage for the wheel.

This particular truck will operate on all I-beams ranging in size from 8" to 15 on all wide flange sizes where the width of the flange does not exceed 6%" and on all Monorail track where the width is at least 4".

One characteristic of this new end truck for the underhung type overhead crane is that the wheels are selfaligning and protected by side guide rollers which roll in a horizontal plane and, in the event of misalignment, will contact the web of the structural I-beam. These side guide rollers act as rolling flanges when needed and also act as safety lugs.

In this combination of a truck for a crane, the crane is free floating as there is no binding action in the flanges. The use of the crowned wheels makes the crane run more freely, and afriction tire drive with the solid rubber tire bearing against the bottom of the runway beam is used to propel the crane. This drive eliminates the troublesome pinions and open gearing atthe end truck and is the basis for using the same unit for push type, hand-geared and motor driven cranes.

The push type, of course, has no drive but is moved along the runway by pushing-the load that is being handled. The crowned flangeless wheels and bearings, as well as the generous size of wheel diameters, provide an easy operating push type crane. i

To convert the push type crane to hand-operated operation, a friction tire drive is bolted to the underside of the end truck, a cross shaft is installed and a hand chain wheel is mounted on the cross shaft. Thus, by a series of additions an initial crane can be purchased that may be converted from push type to hand chain, wheel mounted and later to motor driven, wherein a motor drive with a gear reduction unit will be mounted on the center of the crane bridge and driven directly into the axle of the friction tire drive unit. The motor drive consists of a special motor and a helical spur gear reduction unit mounted in the center of the span of the crane to provide equal drive torque to each end of the crane.

An object of this invention is to provide a new and improved, simplified, underhung type overhead crane and the truck therefor, which is characterized by a crowned wheel riding on a structural I-beam with a friction driven rubber tire unit on the underside of the I-beam.

- A further object of this invention is to provide a new and improved arrangement in a truck for an underhung type overhead crane, which is characterized by having a Wide adaptability to varying sizes of standard structural I-beams for use on the crane runway, each of the runway trucks to be a part of the overhead crane to be driven by any type of push type, hand-operated or motor driven crane, and which is also characterized by a pair of crowned wheels operating on the structural I-beam with side guide rollers to protect the beam, together with a rubber tire drive means on the lower face of the I-beam. To the accomplishmentof the foregoing and related ends, said invention then consists of the means hereinafter fully described and particularly pointed out in the claim; the following description setting forth in detail one approved means of carrying out the invention, such disclosed means, however, constituting but one of the various ways in which the principles of the invention may be used.

In the drawings:

'Fig. l is a schematic perspective view of the crane of this invention, showing in particular the end truck and drive means therefor mounted as an underhung type overhead crane, and also showing in cut-away view the electric drive means therefor;

' Fig. 2 is an end elevational view of the end truck cut away to show the side guide rollers;

Fig. 3 is a plan View of the underhung type overhead crane of this invention, showing the drive means with the I-beam cut away to facilitate the disclosure of the drive means; and

Fig. 4 is a cross-sectional view along theline 44 of Fig. 3, showing the rubber tire drive means, the crowned wheel structure and a cross section of the end truck for said underhung type overhead crane.

Referring now more particularly to the drawings, numeral shows generally an end truck for an overhead crane indicated generally at 11 and adapted for mounting on the flange of an I-beam as at 12. The crane comprises a pair of side channel members 13 and 13' mounted by 'means of a yoke or end member 14 welded together with two pairs of crowned wheels, which are shown generally at 16 mounted on the side channel members, a pair of side guide rollers shown at 17 and a mounting structure therefor as at 18. v

The crane bridge is formed of a pair of the end trucks, above described, and connected together by means of rivets or high-stressed bolts as at 19 to the I-beams for the crane bridge as at 19'.

Suspended in the middle by a series of angle irons, indicated generally. at 20, is a drive motor 21 and a speed reducer 22 connected by means of a drive shaft 23. This, in turn, drives the driven shaft as at 24 to each end of the rubber tire friction drive. The speed reducer is mounted between the trucks on the span of the crane bridge.

This arrangement can be seen more clearly in connection with Fig. 3, and in this view the rubber tire drive unit is shown at 26, the crowned flange wheels are shown at 27 and 28 mounted to ride on the flange of the I-beam 12 as at 29. The side guide rollers 17 are adapted to be spaced slightly from the web 30 of the I-beam 12. The rollers 17 have a mounting structure therefor at 18. The opposite end is identical.

Fig. 4 shows the entire invention, in which a pair of channel members 13 and 13 have secured thereto an end mounting structure 14 and a pair of axle support blocks 35 with the approximate axle means 36, tapered roller bearings 37 and wheels 27 and 28 crowned at 38. The crowned wheels are'hardened to perhaps 500 'Brinell and are adapted to ride on the I-bearn which is a cold rolled section of perhaps 1040 steel and 210 Brinell on the same scale. The tapered flange of this I-beam has a taper as seen at 29 of about 9%, and the crown is of a radius slightly less than the diameter of the wheel. It will be noted that the wheel on the right side in Fig. 4 is operating on the left hand side of the crown, and the opposite would be true in connection with the left hand wheel. These wheels, then, may be reversed after a substantial period of wear, and the surface which has not been in engagement may be used. This doubles the life of the crowned wheels.

It is to be understood that this structure may be used with standard sections of trackway. having flat machine ground surfaces or other types, but this particular structure employing a pair of side flanges and the wheel mounting structure does not employ a flanged wheel and does not need to engage. a specified flange width. In fact, the wheel is shown in engagement at 41, and the edge of the flange of the beam at 29 is spaced by a substantial distance from the channel member 13 and its left face 43. Consequently, this I-beam could have a much wider range and still operate with this type of end truck. The underside of the l-bearn has bolted to it the drive means consisting of the shafting 24, a pillow block structure 44, a series of shims and bolts or other means to secure it to the underside of the truck as at 46. A rubber tire wheel (a solid tire) is shown at 26, and with wear it may be taken up by removal of the shim.

From the above description, it will benoted that this combination of an underhung-type overheadcrane and the truck therefor has particular characteristics and provides for improved rolling characteristics and better drive means under a variety of conditions particularly in connection with the light duty crane field. The characteristics of the crowned wheels in connection with a variety of tapered standard I-beams, as well as the special shapes of the Monorail type, should also be noted. This structure, of course, may be adjusted under varying conditions, and it provides for better centering of the truck on the I-beam as well as improved drive means with longer life because of the reversibility of the crowned wheels. The guide rollers aid substantially in this combination. In general, it is believed that the crown of the wheels should be slightly less than the diameter of the wheel.

Although the present invention has been described in connection with a few preferred embodiments thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of the invention. All of these variations and modifications are considered to be within the true spirit and scope of the present invention as disclosed in the foregoing description and defined by the appended claim.

I claim:

A truck for an underhung type overhead carrier, comprising spaced frame members and at least two pairs of crowned support wheels between said frame members, the wheels of each pair being spaced apart a distance less than the spacing of the frame members, said truck being adapted to roll on any beam having a lower horizontal flange narrower than the spacing between the spaced frame members and wider than the spacing between the support wheels, said beam also having a vertical web substantially bisecting the upper surface of the flange, said frame members being interconnected in substantially parallel relationship, said pairs of support wheels being mounted on the frame members in position to engage and roll along the upper surface of said lower flange, a pair of side guide rollers on each frame member, said guide rollers extending toward said web and being positioned at a height to adapt them to engage the web for rolling contact therealong, and a drive wheel mounted on the frame members and rotatable on an axis generally perpendicular to said web, said drive wheel engaging frictionally the lower surface of the lower flange and bearing adapted to roll therealong to drive said truck along the beam, whereby said truck is adapted to be mounted on any one of a variety of beams having lower flanges of a width less than the spacing of the frame members and greater than the spacing of the crowned support wheels.

UNITED STATES PATENTS Hofiman Feb. 27, 1923 Harris Aug. 8, 1939 Bergren Jan. 9, 1945 Martin Aug. 26, 1952 Nyblom .'Nov. 25, 1958 

